Frequently Asked Questions
To view the FAQs, click on the question to view the answer.
Q: What is the difference between Type I and Type II hoods?
A: Type I hoods are for grease particles, grease vapor and smoke producing applications. Type II is for fumes, steam, odor or heat applications. Type I can also be used for Type II applications but not vice-versa.
Q: I have a small cooking application and need only a small hood. Do I still need a make-up air supply?
A: Yes. NFPA 96 requires that exhausted air be compensated with fresh air because the negative pressure without MUA is a fire hazard.
Q: How much air movement does a system need and is there a minimum required?
A: The required minimum and maximum CFM (cubic feet per minute) are 1,500 CFM minimum and 2,100 CFM maximum.
Q: Can flexible duct connectors be used?
A: No. NFPA 96 requires a rigid bolt-on connection.
Q: My kitchen has a new sprinkler system; do I also need a fire suppression system?
A: Yes. A sprinkler system is inadequate for the quick extinction of grease fires and other kitchen fire hazards.
Q: What kind of power supply will my ventilation system need?
A: A minimum of 20 AMPS is recommended but 15 AMPS is the minimum required for some systems.
Q: How often should I have my system cleaned and degreased?
A: A minimum of twice per year is recommended for small operations, more often for larger applications and those of high grease production. Baffle filters should be cleaned weekly.
Q: I’ve seen hoods made with galvanized steel and even painted metal. Is the cost of S/S worth it?
A: Stainless steel construction is much preferred and worth the investment: It does not create distasteful oxides as it ages; it is all-welded for water-tight integrety that maintains perfect air-flow functionality, is easily cleaned and is more attractive.
Q: I have a long cooking line that requires several hoods set end-to-end. Can the hoods be streamlined into one continuous hood or must the separator walls (end walls) be kept?
A: In most cases, removing the end walls between two butting hoods is an available option. The hoods can be connected with a subtle, continuous edge clip without sacrificing proper exhaust coverage.
Q: My exhuast and supply fans are belt-driven. Do I need to upgrade to direct-drive motors?
A: No, both types are useable. But if you want the advantage of an Energy Logic control panel, upgrading to direct-drive fans is recommended.
Q: Should I consider a water-wash hood or regular hood?
A: An automatic self-cleaning water-wash hood costs more initially but saves you money over time, eliminating many equipment cleaning tasks.
Q: My make-up air unit seems to be working fine. Why would I consider a tempered air handler in its place?
A: Tempered, or pre-cooled make-up air can make a huge difference in comfort for kitchen staff, improving productivity at a lower cost than fully air conditioning the kitchen.
Q: What is meant by 'intelligent' or 'logic' hoods?
A: These terms, including Carroll’s Energy Logic refer to the digital control panel technology that regulates energy use according to the real-time demands of cooking and not the waste of maintaining peak readiness during low-demand and off hours. The Energy Logic option is a huge money-saver over time.